Each year more than 100,000 US women seek emergency medical care after sexual assault (SA). Most women do not return for/receive further care related to SA after initial emergency evaluation. Thus the emergency care visit represents a unique opportunity to identify SA survivors for preventive interventions to improve recovery. Cross-sectional studies indicate that chronic musculoskeletal pain (MSP) is reported by many SA survivors and is associated with substantial suffering and poor health outcomes. However, no prospective studies evaluating chronic MSP outcomes after SA have been performed, and therefore a firm etiologic link between SA and chronic MSP has not been established. In a recent prospective pilot study (n = 83), the investigators found that 41% of women SA survivors enrolled developed chronic moderate or severe MSP. Initial pain scores collected from all women approached for pilot study participation showed that more than half of those at high risk of chronic MSP consented and enrolled in the pilot study. In addition, data collected indicate that women SA survivors who participated in the pilot study are the same group of SA survivors who would be willing to participate in preventive intervention trials. However, currently no informatio exists regarding key factors that influence the transition from acute to chronic post-SA MSP to inform the design of such trials. Available evidence suggests that posttraumatic stress disorder (PTSD) symptoms may be key factors mediating the transition from acute to chronic post-SA MSP. PTSD symptom clusters have been found to mediate the transition from acute to chronic MSP in other trauma populations, and the investigator's pilot data support these relationships in the study population. Importantly, despite evidence that PTSD symptoms are key factors mediating chronic post-SA MSP development, available data also indicate that not all individuals with acute MSP develop PTSD symptoms, and not all individuals with PTSD symptoms develop chronic MSP. This suggests that important individual differences moderate these relationships. Available evidence, and the investigator's pilot data, suggests that genetic variants affecting the function of hypothalamic-pituitary-adrenal (HPA) and catecholaminergic systems constitute such important individual differences. The investigators propose a prospective cohort study of women SA survivors (n = 900) evaluated 1 week, 6 weeks, 6 months, and 12 months after SA. A methodological approach including Confirmatory Factor Analyses and Structural Equation Modeling will be used to test the hypotheses that chronic MSP is common in the study population, that PTSD symptom clusters mediate the relationship between acute and chronic MSP after SA, and that the proposed genetic factors moderate these relationships. Results of this groundbreaking study will generalize to a large population of women SA survivors who experience a high burden of chronic post-SA MSP, and will inform the development of preventive interventions for this understudied population.